Data outputting method, recording method and apparatus, reproducing method and apparatus, and data transmitting method and receiving method

ABSTRACT

A data outputting method, including the steps of converting input data into sector unit data that starts with a start code and a header preceded by the start code, the header being composed of two bits, at least one of which represents an encryption control; when the converted data is to be encrypted, setting at least one of the two bits preceded by the start code to a state that represents that the data has been encrypted; encrypting the converted data; encoding the encrypted data; and outputting the encoded data.

TECHNICAL FIELD

The present invention relates to a data outputting method, a recordingmethod and apparatus, a reproducing method and apparatus, and a datatransmitting method and receiving method that allow different dataformats to be merged.

BACKGROUND ART

In a hard disk drive, a floppy (trademark) disk drive, CD-ROM/CD-R/CD-RWdisc drives, and so forth, which are external storing apparatuses forpersonal computers, data is processed in the unit of a sector. Forexample, the size of one sector is 2 Kbytes (2048 bytes). To protect thecopyright of contents, contents data is encrypted and recorded. Toencrypt contents data in the unit of a sector, each sector requires anencryption control bit. In the CBC (Chaining Block Ciphering) mode, anIV (Initial Vector: encryption initial value) is required.

As a transmitting or recording format for multimedia contents data, theMPEG (Moving Picture Experts Group) is known. FIG. 1A shows a datastructure of a program stream corresponding to the MPEG2 system. Oneprogram starts with a pack header and ends with an end code. Generally,a pack is composed of a plurality of packets. A system header is addedto the top pack. The system header is optionally added to the laterpackets. A pack header is added at the beginning of each pack.

As shown in FIG. 1A, the pack header is composed of a pack start code(32 bits), an identification code (2 bits), an SCR (System ClockReference: system time reference value) (42+4 bits), a multiplexing rate(22+2 bits) that represents the bit rate of the stream, a stuffinglength (3+8 bits), and a stuffing byte (8×M bits). The stuffing byte isdummy data used to keep for example the packet data length constant.Thus, the stuffing byte does not have meaningful information.

FIG. 1B shows the structure of a packet. At the beginning is a packetstart code (32 bits) placed. The packet start code is composed of abeginning start code and a stream ID (8 bits). The packet start code isfollowed by a packet length (16 bits) that represents the data length ofa packet. A control code (2 bits) is “01” in the MPEG2 system. The firsttwo bits of a flag and control (14 bits) are used for a PES (PacketizedElementary Stream) scramble control. A PES header length (8 bits)represents the header length. Corresponding to the flag and control,conditional coding items are placed. The conditional coding itemscontains a PTS (Presentation Time Stamp) (33+7 bits), a DTS (DecodingTime Stamp) (33+7 bits), and data of other codes. In addition, astuffing byte (8×M bits) is added. The stuffing byte is followed bypacket data (8×N bits).

FIG. 2 shows a data structure for 2 Kbytes in the MPEG2 system to bemerged with the data format of a conventional application with a sectorlength of 2 Kbytes (2048 bytes) (hereinafter sometimes referred to asconventional data format). As shown in FIG. 2, one pack is composed ofone packet. The size of one pack is 2 Kbytes. Thus, one pack isequivalent to one sector of the conventional format. At the top of onepack is a pack header (14 bytes) placed. The pack header is followed bya PES header (14 bytes), a stream header (4 bytes), and user data (2016bytes) in the order. When the user data is divided in the unit of eightbytes, the user data (or packet) is composed of D1 to D252. The userdata is for example audio data that has been compression-encoded andencrypted. Thus, the data structure shown in FIG. 2 satisfies the MPEG2system coding rule.

Although the pack header shown in FIG. 2 is the same as that shown inFIG. 1A, since the pack header shown in FIG. 2 does not contain astuffing byte, the length thereof is 14 bytes. In other words, the packheader is composed of a pack start code (32 bits), a control code (2bits), an SCR (42+4 bits), a multiplexing rate (22+2 bits) thatrepresents the bit rate of the stream, and a stuffing length (3+5 bits),which is a total of 112 bits (=14 bytes). The stuffing byte is not addedso as to prevent the stuffing byte from varying the position of thescramble control bit.

Although the PES header shown in FIG. 2 is the same as that shown inFIG. 1B, the PES header shown in FIG. 2 is composed of a packet startcode (32 bits), a packet length (16 bits), a two-bit control code, aflag and control (14 bits), a PES header length (8 bits), and a PTS(33+7 bits), which is a total of 112 bits (=14 bytes).

The stream header (4 bytes) contains information that represents audiocoding method (linear PCM, MP3 (MPEG1 Audio Layer III), AAC (AdvancedAudio Coding), ATRAC3 (Adapive Transform Acoustic Coding 3, or thelike), a bit rate (64 Kbps or the like), the number of channels(monaural, stereo, 5.1 channels, or the like), and so forth.

Bit numbers are added to 32 bytes (=256 bytes) of the pack header, thePES header, and the stream header to define bit positions. When the topbit is bit 0, the pack header is from bit 0 to bit 111; the PES headeris from bit 112 to bit 223; and the stream header is from bit 223 to bit255. In the PES header, the scramble control bits of the flag andcontrol are from bit 162 to bit 163. The scramble control bits have beendefined as “00”=non-scrambled; “01”=scrambled; and “10” and“11”=reserved (not defined).

The two-bit control code of bit 32 and bit 33 of the pack header is “00”has been defined as “00”=MPEG1 system; and “01”=MPEG2 system. In theMPEG1 system, no scramble control bits are used. As the IV necessary forencryption, the SCR of the pack header, the PTS of the PES header, orthe like is used.

FIG. 3A shows the data structure for one sector in a conventional dataformat (that means the data format of a conventional application otherthan the MPEG systems). Assuming that encrypting is performed with theIV in the CBC (Chaining Block Ciphering) mode (normally mostly, aprocess in the unit of eight bytes), the top eight bytes contain data ofthe scramble control, the IV, and so forth. For example, four bytes areused as the IV. 2040 bytes of which the sector header is excluded formone sector are user data. In other words, the user data is composed of2040 bytes. When the user data is divided in the unit of eight bytes, itcontains data D1 to D255.

It is preferred to allow for example a personal computer, an opticaldisc drive, and application software (hereinafter referred to as driveand so forth) to deal with both the data format corresponding to theforgoing MPEG2 system and the conventional data format shown in FIG. 3A.For example, conventional application data is dealt with theconventional data format, whereas audio and video data are dealt withdata corresponding to the MPEG2 system. When audio and video data are ina data format corresponding to the MPEG2 system, the audio data and thevideo data can be multiplexed with data of the conventional application.For example, sound and a song text image can be recorded at a time. Withthe PTS, which is a time stamp, even if data has beencompression-encoded with a variable length code, the data can beaccessed at high speed.

When two different data formats are used, the drive and so forth mayidentify the data formats and selectively access data thereof. In thismethod, however, it is difficult for the drive and so forth to identifythe two different formats. To judge whether data has been encrypted inthe unit of a sector, the drive and so forth should look up bits atdifferent positions corresponding to the MPEG2 system and theconventional data format. Thus, it is difficult for the drive and soforth to judge whether data has been encrypted in the unit of a sector.

As another method, two different data formats are merged. In thismethod, such a problem about the selection of the formats does notarise. FIG. 3B shows the data structure in the case that theconventional data format is fit to the MPEG2 system. In the MPEG2system, the top 32 bytes are a pack header, a PES header, and a streamheader as shown in FIG. 2A. Information (scramble control bits and IV)contained in the sector header (eight byes) in the conventional dataformat can be composed of 32 bytes. However, although the conventionaldata format needs a header of only eight bytes, the format correspondingto the MPEG2 system needs a header of 32 bytes. Thus, (32−8=24 bytes)are wasted. In other words, the user data of one sector is decreasedfrom 2040 bytes to 2016 bytes. In addition, to fix the positions of thescramble control bits in the MPEG2 system, the stuffing byte cannot beused.

On the other hand, when the MPEG2 system is fit to the conventional dataformat, as shown in FIG. 3C, a header of eight bytes is added at thebeginning of one sector in the data format of the MPEG2 system. As aresult, no problem will arise in applications corresponding to otherthan the MPEG2 system format. However, in applications corresponding tothe MPEG2 system, the top eight bytes will be wasted.

Therefore, an object of the present invention is to provide a dataoutputting method, a recording method and apparatus, a reproducingmethod and apparatus, and a data transmitting method and receivingmethod that prevent data from being wasted and user data from beingdecreased and that allow data structures of different systems to bemerged.

DISCLOSURE OF THE INVENTION

To accomplish the forgoing object, an aspect of the present invention isa data outputting method, comprising the steps of converting input datainto sector unit data that starts with a start code and a headerpreceded by the start code, the header being composed of two bits atleast one of which is a bit that represents an encryption control; whenthe converted data is to be encrypted, setting at least one of the twobits preceded by the start code to a state that represents that the datahas been encrypted; encrypting the converted data; and encoding theencrypted data and outputting the encoded data.

Another aspect of the present invention is a recording method,comprising the steps of converting input data into sector unit data thatstarts with a start code and a header preceded by the start code, theheader being composed of two bits at least one of which is a bit thatrepresents an encryption control; when the converted data is to beencrypted, setting at least one of the two bits preceded by the startcode to a state that represents that the data has been encrypted;encrypting the converted data; and performing an encoding process forthe encrypted data and recording the encoded data on a recoding medium.

A further aspect of the present invention is a recording apparatus,comprising a converting portion for converting input data into sectorunit data that starts with a start code and a header preceded by thestart code, the header being composed of two bits at least one of whichis a bit that represents an encryption control; a setting portion forsetting at least one of the two bits preceded by the start code to astate that represents that the data has been encrypted when dataconverted by the converting portion is to be encrypted; an encryptingprocess portion for performing an encrypting process for output data ofthe setting portion; an encoding process portion for performing anencoding process for output data of the encrypting process portion sothat the output data is recorded; and a recording portion for recordingoutput data of the encoding process portion to a recording medium.

A still further aspect of the present invention is a reproducing method,comprising the steps of decoding data that has been read from a recodingmedium on which sector unit data had been recorded, the sector unit databeing composed of user data, a start code, and a header, the sector unitdata starting with the start code and the header preceded by the startcode, the header being composed of two bits, at least one of whichrepresents an encryption control; detecting at least one of the two bitspreceded by the start code of the decoded data; when the detected resultrepresents that the decoded data has been encrypted, decrypting thedecoded data; and converting the decrypted data as the sector unit datainto predetermined unit data and outputting the predetermined unit data.

A still further aspect of the present invention is a reproducingapparatus, comprising a decoder for decoding data that has been readfrom a recoding medium on which sector unit data had been recorded, thesector unit data being composed of user data, a start code, and aheader, the sector unit data starting with the start code and the headerpreceded by the start code, the header being composed of two bits, atleast one of which represents an encryption control; a detecting portionfor detecting at least one of the two bits preceded by the start code ofoutput data of the decoder; a decrypting portion for decrypting theoutput data of the decoding portion when the detected result of thedetecting portion represents that the decoded data has been encrypted;and a converting portion for converting output data of the decryptingportion as the sector unit data into predetermined unit data andoutputting the predetermined unit data.

A still further aspect of the present invention is a data transmittingmethod, comprising the steps of converting input data into sector unitdata that starts with a start code and a header preceded by the startcode, the header being composed of two bits at least one of which is abit that represents an encryption control; when the converted data is tobe encrypted, setting at least one of the two bits preceded by the startcode to a state that represents that the data has been encrypted;encrypting the converted data; and performing an encoding process forthe encrypted data and transmitting the encoded data.

A still further aspect of the present invention is a data receivingmethod, comprising the steps of receiving sector unit data composed ofuser data, a start code, and a header, the sector unit data startingwith the start code and the header preceded by the start code, theheader being composed of two bits, at least one of which is a bit thatrepresents an encryption control; decoding the received data; detectingat least one of the two bits preceded by the start code of the decodeddata; when the detected result represents that the decoded data has beenencrypted, decrypting the decoded data; and converting the decrypteddata as the sector unit data into predetermined unit data.

Since two bits at predetermined positions are used for an encryptioncontrol, two different systems for example MPEG2 system and conventionalapplication can be merged without waste and inconsistency of data.Moreover, an encryption control can be performed in the unit of asector. Furthermore, in the MPEG1 system, which does not define scramblecontrol bits, an encryption control can be performed. As a result, thesecurity of contents in the MPEG1 format can be protected. In addition,since the positions of the encryption initial values of these dataformats are the same, the same encrypting system can be used. After datahas been decrypted, the decrypted data can be used as data correspondingto the MPEG1 system and the MPEG2 system. Since the MPEG systems placeencryption control bits at fixed positions preceded by a stuffing byte,it can be used.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a schematic diagram showing the data structure of a programstream corresponding to the MPEG2 system according to the presentinvention;

FIG. 1B is a schematic diagram showing the structure of a packetcorresponding to the MPEG2 system according to the present invention;

FIG. 2 is a schematic diagram showing an example of the data structurecorresponding to the MPEG2 system;

FIG. 3A is a schematic diagram showing the data structure of one sectorin a data format of a conventional application;

FIG. 3B is a schematic diagram showing the data structure in the casethe data format of the conventional application is fit to the MPEG2system;

FIG. 3C is a schematic diagram showing the data structure in the casethat the MPEG2 system is fit to the data format of the conventionalapplication;

FIG. 4A is a schematic diagram showing the data structure (for example,one sector is composed of 2 Kbytes) according to an embodiment of thepresent invention;

FIG. 4B is a schematic diagram showing a part of the data structure inthe case that the present invention is applied to the MPEG2 system;

FIG. 4C is a schematic diagram showing a part of the data structure inthe case that the present invention is applied to the conventional dataformat other than the MPEG2 system;

FIG. 5A is a schematic diagram showing an example of a definition ofencryption control bits according to an embodiment of the presentinvention;

FIG. 5B is a schematic diagram showing another example of the definitionof the encryption control bits according to an embodiment of the presentinvention;

FIG. 6 is a block diagram showing a recording apparatus and atransmitting apparatus according to an embodiment of the presentinvention;

FIG. 7 is a block diagram showing a reproducing apparatus and areceiving apparatus according to an embodiment of the present invention;

FIG. 8 is a block diagram showing an example of an encrypter accordingto the present invention; and

FIG. 9 is a block diagram showing an example of a decrypter according tothe present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

Next, an embodiment of the present invention will be described. Atfirst, with reference to FIG. 4A to FIG. 4C, a data format according tothe embodiment will be described. FIG. 4A shows an example of which onesector is composed of 2 Kbytes (2048 bytes). However, 2 Kbytes is justan example. In other words, one sector may be composed of other than 2Kbytes. In the top eight bytes (bit 0 to bit 63) of one sector, two bitsof bit 32 (denoted by a1) and bit 33 (denoted by a2) are used as anencryption control code. The two bits a1 and a2, which are a controlcode, and the remaining 30 bits, which is a total of 32 bits, are usedas an IV. With the IV, the data after bit 64 is encrypted in the CBCmode. However, data after any bit other than bit 64 (for example, dataafter bit 128) may be encrypted.

FIG. 4B shows a part of the data structure in the case that the presentinvention is applied to the MPEG2 system. In other words, as wasdescribed with reference to FIG. 2, the top 32 bits correspond to thepack start code. The 32 bits are followed by the control code (a1 anda2). The control code (a1 and a2) is followed by an SCR of (42+2) bits.Thus, the control code is used for a scramble control. The IV iscomposed of 30 bits of the SCR. Data after bit 64 is encrypted with theIV. The size of the user data is 2016 bytes as with the case shown inFIG. 2.

In the MPEG2 system, scramble control bits are assigned to bits 162 and163. The scramble control bits have been defined as “00”=non-scrambled;“01”=scrambled; and “10” and “11”=reserved (not defined). When thecontrol code (a1 and a2) is are used for an encryption control accordingto the embodiment, it has been prescribed that information of thecontrol code should not be inconsistent with information of the scramblecontrol bits. Alternatively, the information of the control code has theprecedence over the other. In other words, when the control coderepresents scrambled, this state is used regardless of the scramblecontrol bits.

FIG. 4C shows an example of the case that the present invention isapplied to the conventional data format other than the MPEG systems. Thetop 32 bits are reserved or used as a system header. The 32 bits arefollowed by a two-bit control code a1 and a2. The remaining 30 bits area random number generated by hardware or software. The control code a1and a2 and the random number correspond to the IV. However, when the IVneeds the length of 64 bits, two sets of 32 bits from bit 32 to bit 63or data from bit 0 to bit 63 may be used. Data after bit 64 is userdata. As with the data structure shown in FIG. 3A, the size of the userdata is 2040 bytes.

FIG. 5 shows two examples of the definition of the two-bit control code(a1 and a2). In the example shown in FIG. 5A, to identify MPEG1 andMPEG2, two bits are used. “a1 a2”=“0 1” has been defined asnon-encrypted in the MPEG1 system. “a1 a2”=“0 1” has been defined asnon-encrypted in the MPEG2 system. They comply with the definition ofthe MPEG. “a1 a2”=“1 0” has been defined as encrypted in the MPEG1system. “a1 a2”=“1 1” has been defined as encrypted in the MPEG2 system.When the MPEG1 system is not used, “a1 a2”=“0 0” and “a1 a2”=“1 0” maybe undefined (reserved).

Only bit 32 (a1) may be used for an encryption control. In this case,“a1 a2”=“0 0” is defined as non-encrypted in the MPEG1 system. “a1a2”=“0 1” is defined as non-encrypted in the MPEG2 system. “1x” (where xrepresents one of “0” and “1”) is defined as encrypted.

In the other example shown in FIG. 5B, two bits are used for anencryption control. “a1 a2”=“0 0” is defined as reserved. “a1 a2”=“0 1”is defined as non-encrypted. “a1 a2”=“1 0” is defined as encrypted inthe second encrypting method. “a1 a2”=“1 1” is defined as an encryptionin the first encrypting method, which is different from the secondencrypting method. In the first and second encrypting methods,encrypting keys or encrypting methods are different. As a method forcausing encrypting keys to be different, a key Ka in the firstencrypting method is Hash-calculated and thereby a key Kb in the secondencrypting method is obtained. Alternatively, keys which do have norelation at all may be used.

Different encrypting methods are used for different contents types. Forexample, the encrypting method used for trial listening contents isdifferent from that used for contents to be-charged. The key Ka in theforgoing example is used for decrypting data of contents to be charged.The key Kb is used for decrypting data of trial listening contents.Although the data of the key Kb can be generated by a Hash calculationfor the key Ka, the data of the key Ka cannot be generated by a Hashcalculation of the key Kb because the Hash function is unidirectional.

In the example shown in FIG. 5B, when the two bits “a1a2” representsencrypted, when encrypted data is decrypted, the two bits are changed toa value that represents non-encrypted. In the MPEG1 system, when data ofcontents is decrypted, “a1 a2” is rewritten to “0 0”. In the MPEG2system, when data of contents is decrypted, “a1 a2” is rewritten to “01”. The reserved two bits may represent a third encrypting method.

Next, with reference to FIG. 6, an embodiment of a recording apparatusand a transmitting apparatus according to the present invention will bedescribed. In FIG. 6, the recording apparatus and the transmittingapparatus are illustrated on the same drawing. However, they arenormally structured as independent systems. Referring to FIG. 6,reference numerals 1 a, 1 b, and 1 c represent input terminals to whichvideo data, audio data, and text data are input. When necessary, thesedata are compressed data. They are delimited in the data length of apacket.

The data that are input from the input terminals 1 a to 1 c aretime-division multiplexed by a multiplexer 2. The multiplexed data issupplied to an MPEG judging portion 3. The MPEG judging portion 3decides the system to be used. The MPEG judging portion 3 decides thesystem to be used corresponding to for example user's selection, thejudgment of the application software, the control information inassociation with the input data, and so forth.

When the judged result of the MPEG judging portion 3 represents that theMPEG1 system is to be used, the multiplexed data is supplied to an MPEG1system converting portion 4. When the judged result of the MPEG judgingportion 3 represents that the MPEG2 system is to be used, themultiplexed data is supplied to an MPEG2 system converting portion 5.When the judged result of the MPEG judging portion 3 represents that theconventional application is to be used, the multiplexed data is suppliedto a random number generating portion 6. As shown in FIG. 4C, the randomnumber generating portion 6 generates output data of a data structure ofwhich reserved or system header, two bits, and a random number have beenadded to each sector.

The MPEG1 system converting portion 4 converts the multiplexed data intoa data structure corresponding to the MPEG1 system. The MPEG2 systemconverting portion 5 converts the multiplexed data into a data structurecorresponding to the MPEG2 system of which a pack header (a pack startcode, two bits, an SCR, a multiplexing rate, and a stuffing length), aPES header, and a stream header have been added to each pack (sector) asshown in FIG. 2 and FIG. 4B. Although the data structure correspondingto the MPEG1 system is almost same as that shown in FIG. 4B, the formerdata structure does not contain scramble control bits.

Output data of the MPEG1 system converting portion 4, the MPEG2 systemconverting portion 5, and the random number generating portion 6 aresupplied to an encryption judging portion 7. The encryption judgingportion 7 judges which of output data of the MPEG1 system convertingportion 4, the MPEG2 system converting portion 5, and the random numbergenerating portion 6 is to be encrypted. When a plurality of encryptingmethods are provided, the encryption judging portion 7 selects one fromthe plurality of encrypting methods. The encryption judging portion 7judges whether to encrypt data corresponding to a selection by the user(for example, contents creator), a judgment by application software, acommand of an authoring system, control information in association withinput data, and so forth.

When the judged result represents that the data is to be encrypted,output data of the encryption judging portion 7 is supplied to a bitsetting circuit 8. The bit setting circuit 8 outputs data in which a1=“1” has been set. The data in which a1=“1” has been set is supplied toan encrypter 9. The encrypter 9 encrypts the data. The encrypter 9encrypts data after bit 64 in the data structure shown in FIG. 4B andFIG. 4C. The encrypter 9 encrypts the data in the CBC mode with an IV(initial value). In the MPEG1 and MPEG2 systems, the IV is a part of theSCR. In the conventional data format, the IV is a random numbergenerated by the random number generating portion 6. As shown in FIG.5A, the data in which a1=“1” has been set by the bit setting circuit 8represents that the data of the sector has been encrypted. When thejudged result of the encryption judging portion 7 represents that thedata is not to be encrypted, the output data of the encryption judgingportion 7 is supplied to a bit setting circuit 10. The bit settingcircuit 10 sets the bit a1 to “0”.

The data that has been encrypted by the encrypter 9 or output data ofthe bit setting circuit 10 is supplied to an error correction codeencoding circuit 11. The error correction code encoding circuit 11encodes the data with an error correction code. Output data of the errorcorrection code encoding circuit 11 is supplied to a modulating circuit12.

In the recording apparatus, output data of the modulating circuit 12 issupplied to an optical pickup 14 through a recording amplifier 13. Theoptical pickup 14 records the data on an optical disc 15. The opticalpickup 14 is traveled in the radial direction of the optical disc 15 bya feed motor (not shown). The optical disc is a recordable optical disc.The optical disc 15 is rotated and driven at constant linear velocity orconstant angular velocity by a spindle motor 16. In the recordingapparatus, a tracking servo and a focusing servo for the optical pickup14 and a servo circuit (not shown) that controls the rotation of thespindle motor 16 are disposed.

The optical disc 15 according to the embodiment is a phase change typedisc. In the phase change type disc, when laser light in a sufficientoutput level is radiated to the optical disc 15, data can be recordedthereon. When the variation of the light amount of the laser lightreflected by the optical disc 15 is detected, the data recorded on theoptical disc 15 can be reproduced. The material of a substrate on whicha recording film composed of a phase change recording material of theoptical disc 15 is coated is for example polycarbonate. Thepolycarbonate has been injection molded so that track guide groovessimply referred to as grooves have been formed. Since the grooves formedon the disc substrate have been formed, they are also referred to aspre-grooves. A portion between two grooves is referred to as land.Normally, it is prescribed that the near side viewed from the incidentside of read laser light is a groove and that the far side thereof is aland. The grooves have been successively and spirally formed from theinner circumference to the outer circumference. In addition, as long asthe disc is recordable, the present invention can be applied to not onlya phase change type optical disc such as a CD-RW disc, but amagneto-optical disc and a write-once type disc such as a CD-R disc,which uses an organic coloring matter as a recording material.

The grooves have been wobbled in the radial direction of the opticaldisc 15 so that they are used as a reference signal for controlling therotation of the optical disc 15 and for recording data thereon. Data isrecorded in-grooves or at grooves and lands of the optical disc 15. Inaddition, the grooves have been wobbled in the radial direction of theoptical disc 15 so as to successively record absolute time informationand clock as address information. In the CD-R disc and the CD-RW disc,with reference to the absolute time information as the addressinformation of which the grooves wobbled in the radial direction of thedisc have been optically detected, the optical pickup 14 is traveled toa desired data write position on the optical disc 15. Laser light isradiated from the optical pickup 14 to the optical disc 15. As a result,data is written at the desired position of the optical disc 15.

The optical disc having wobbled grooves is produced in the followingmanner. A mastering apparatus radiates laser light on a photo resistfilm coated on a glass master disc and deflects or swings the laserlight in the radial direction of the glass master disc. As a result,wobbled grooves are formed. The photo resist film exposed by theradiation of the laser light is developed. As a result, a maser disc isproduced. An electroforming process is performed for the maser disc. Asa result, a stamper is produced. With the stamper, injection molding isperformed. As a result, a disc substrate having wobbled grooves isformed. A phase change recording material is coated on the groove-formedsurface of the disc substrate by for example spattering method. As aresult, the optical disc 15 is produced.

Alternatively, the recording apparatus shown in FIG. 6 may beaccomplished by a drive (hardware) and a personal computer (software)besides dedicated hardware. The structure downstream of the errorcorrection code encoding circuit 11 is hardware (a drive such as a CD-Rdrive or a CD-R/W drive). The rest can be accomplished by softwareexecuted by a microcomputer or the like as a controller. In therecording apparatus, as an example of the physical format, the CD-ROMmode 2, form 1 is used. As the file management system, the UDF(Universal Disc Format) is used. As the application, the MPEG1 system,the MPEG2 system, or the conventional application is used. When adifferent application is used, as was described with reference to FIG.4A to FIG. 4C, data is recorded in the merged data format on the opticaldisc or transmitted.

In the transmitting apparatus, output data of the modulating circuit 12is supplied to a transmitting antenna 18 through a transmittingamplifier 17. A signal is transmitted from the transmitting antenna 18to for example a communication satellite. As another transmitting methodother than the method using a communication satellite, the presentinvention can be applied to the case that output data is transmittedfrom the modulating circuit 12 through the internet.

FIG. 7 shows a reproducing apparatus and a receiving apparatus accordingto an embodiment of the present invention. As with the recordingapparatus, the reproducing apparatus is composed of a disc drive (aCD-ROM drive, a CD-R drive, a CD-RW drive, or the like), which isstructured as hardware, and application software, which is executed by acontroller. Alternatively, the reproducing apparatus shown in FIG. 7 maybe structure as hardware.

In FIG. 7, an optical disc 15 is rotated by a spindle motor 22. Anoptical pickup 23 reads data from the optical disc 15. Laser lightnecessary for reproducing data is radiated from the optical pickup 23 tothe optical disc 15. A four-divided photo-detector disposed on theoptical pickup 23 detects laser light reflected by the optical disc 21.A signal detected by the photo-detector as an output signal is suppliedto a reproduction RF processing portion 24.

The reproduction RF processing portion 24 calculates the detected signalof the photo-detector by a matrix amplifier disposed therein andgenerates a reproduction (RF) signal, a tracking error signal, and afocus error signal. When clock and addresses have been recorded aswobbled grooves, a signal of which the wobbled grooves have beendetected is output from the reproduction RF processing portion 24. An RFsignal generated by the reproduction RF processing portion 24 issupplied to a demodulating portion 25. The demodulating portion 25performs for example an EFM demodulating process corresponding to thesupplied RF signal.

In the receiving apparatus, a signal received by a receiving antenna 26is supplied to a reception RF processing portion 27. The reception RFprocessing portion 27 performs a frequency converting process and soforth. An output signal of the reception RF processing portion 27 issupplied to the demodulating portion 25. The demodulating portion 25performs a demodulating process for the signal. Output data of thedemodulating portion 25 is supplied to an error correcting circuit 28.The error correcting circuit 28 performs an error detecting and errorcorrecting process.

A tracking error signal and a focus error signal generated by thereproduction RF processing portion 24 are supplied to a servo circuit(not shown). The servo circuit controls the rotation of the spindlemotor 22 and tracking and focus of the optical pickup 23. The servocircuit performs a tracking servo and a focus servo for the opticalpickup 23, a spindle servo for the spindle motor 22, and a thread servofor traveling the optical pickup 23 in the radial direction of theoptical disc 15.

Data that has been error-corrected by the error correcting circuit 28 issupplied to a bit detecting circuit 29. The bit detecting circuit 29judges whether bit a1 is “0” or “1”. When the detected result of the bitdetecting circuit 29 represents that a1=“1”, since the reproductiondata, which is output data of the error correcting circuit 28, has beenencrypted, the reproduction data is supplied to an IV reading portion30. As shown in FIG. 4A to FIG. 4C, since the position of the IV of thereproduction data is fixed, the IV reading portion 30 can easily readthe IV.

The IV that has been read by the IV reading portion 30 and the encrypteddata are supplied to a decrypter 31. The decrypter 31 performs a processfor decrypting encrypted data (namely, a decrypting process). Outputdata (namely, decrypted data) of the decrypter 31 is supplied to a bitsetting circuit 32. The bit setting circuit 32 sets bit a1 of the datawhich is output from the decrypter 31 to “0”, which representsnon-encrypted. The resultant two bits of which bit a1 has been set to“0” comply with the rule of the MPEG2 system. The data, of which bit a1has been set to “0” by the bit setting circuit 32, is supplied to anMPEG judging portion 33. When the detected result of the bit detectingcircuit 29 represents that bit a1 is “0”, since output data of the errorcorrecting circuit 28 has not been encrypted, the data is supplied tothe MPEG judging portion 33 as it is.

The MPEG judging portion 33 judges whether the input data corresponds tothe MPEG1 system, the MPEG2 system, or the conventional application. Thejudgment of whether the input data corresponds to the MPEG1 system orthe MPEG2 system is performed depending on whether the data containsscramble control bits. On the other hand, the judgment of whether theinput data corresponds to the conventional application is performeddepending on whether or not the portion of the SCR is a random number.When the input data corresponds to the MPEG1 system, the reproductiondata is processed by an MPEG1 system processing portion 34. When theinput data corresponds to the MPEG2 system, the reproduction data isprocessed by an MPEG2 system processing portion 35. The MPEG1 systemprocessing portion 34 and the MPEG2 system processing portion 35 performrespective decoding processes for data corresponding to the respectivesystems and output video data and audio data, which have been delimitedby packs.

When the judged result of the MPEG judging portion 33 represents thatthe input data corresponds to the conventional application, the data issupplied to a demultiplexer 36 as it is. Video data and audio data,which have been processed by the MPEG1 system processing portion 34 orthe MPEG2 system processing portion 35, are supplied to thedemultiplexer 36. The demultiplexer 36 groups these data and outputs thegrouped data to output terminals 37 a, 37 b, and 37 c.

FIG. 8 shows an example of the encrypter 9 (refer to FIG. 6) in the CBCmode. For example, data Mi delimited every for example 64 bits (eightbytes) is supplied to a mod 2 adding device 41 (for example, anexclusive OR gate). When the top data of one sector is M1, an IV(initial value) is supplied to the adding device 41. An output of theadding device 41 is supplied to a block encrypter 42. The blockencrypter 41 is an encrypter that performs an encrypting processcorresponding to DES (Data Encryption Standard), AES, triple DES, or thelike.

Key data (128 bits) is supplied to the block encrypter 42. The blockencrypter 42 encrypts an output of the adding device 41 with the keydata. The block encrypter 42 outputs encrypted data E (Mi) (64bits). Theencrypted data E (Mi) is output from the block encrypter 42. Inaddition, the encrypted data E (Mi) is fed back to the adding device 41.The adding device 41 adds the next input data M2 to the encrypted data E(Mi). The same operation is repeated until data for one sector has beenprocessed.

FIG. 9 shows an example of the structure of the decrypter 31 (refer toFIG. 7) corresponding to the encrypter 9. As was described above,encrypted data E (Mi) is supplied to a block decrypter 43. Key data issupplied to the block decrypter 43. The block decrypter 43 decrypts thedata E (Mi). The decrypted data is supplied to a mod 2 adding device 44.At the first time, the adding device 44 adds an IV of the sector and theoutput data of the block decrypter 43. At the second or later time, theadding device 44 adds the output data of the block decrypter 43 and theinput data thereof. The adding device 44 outputs decrypted data Mi.

The present invention is not limited to the forgoing embodiment.Instead, without departing from the scope and sprit of the presentinvention, various modifications and ramifications are available. Forexample, in the reproducing apparatus and the receiving apparatus, afterdata is decrypted, bit a1 is set to “0”. Alternatively, without such aprocess, after data has been decrypted, bit a1 may be ignored. Inaddition, when the recording method according to the present inventionis applied to a read-only optical disc, the recording apparatus shown inFIG. 6 is applied to a mastering apparatus. In addition, the presentinvention can be applied to not only optical discs, but other datarecording mediums such as memory cards.

According to the present invention, in a data format of which data ofdifferent systems such as the MPEG system and conventional applicationhave been merged, an encryption control can be performed in the unit ofa sector. Thus, it is not necessary to identify data of these twosystems and selectively perform the processes. In addition, when datastructures are merged, the amount of data that is placed in one sectoris not decreased. Thus, efficiency is assured. In addition, as themerged result of data of the systems, they are not inconsistent.

According to the present invention, in each system, an encryptinginitial value can be placed at the same position in a sector. Data ofdifferent systems can be encrypted and decrypted in the same method. Inaddition, in the MPEG1 system, which has not defined a scramble control,each sector can contain information of an encryption control. As aresult, the security (copyright) of contents can be protected. Afterencrypted data has been decrypted, when bits are rewritten, thedecrypted data can be used in the MPEG1 system and the MPEG2 system. Inaddition, when stuffing bytes are added, the positions of bits for anencryption control are fixed. As a result, variable length data can behandled.

1. A data outputting method, comprising the steps of: converting inputdata into sector unit data that starts with a header including two bitssubsequent to a start code wherein at least one bit of the two bitsrepresents an encryption control; setting at least one of the two bitssubsequent to the start code into the sector unit data so as torepresent that the data has been encrypted, when the sector unit data isencrypted; encrypting the converted data; encoding the encrypted data;and outputting the encoded data; wherein data of one sector of thesector unit data is composed of 2048 bytes, wherein the encrypting stepis performed by encrypting data after bit 64, in which the two bitssubsequent to the start code are located in a same position for aplurality of format systems, wherein the converting step comprises thesteps of: judging whether the input data is to be converted into thesector unit data corresponding to an MPEG encoding rule; and convertingthe input data corresponding to the MPEG encoding rule, when the judgedresult represents that the input data is to be converted into the sectorunit data corresponding to the MPEG encoding rule, and wherein when thejudged result represents that the input data is not to be converted intothe sector unit corresponding to the MPEG encoding rule, the convertingstep further comprises the step of: adding random number data to thesector unit data so that the random number data is followed by the startcode and the two bits.
 2. A recording method, comprising the steps of:converting input data into sector unit data that starts with a headerincluding two bits subsequent to a start code wherein at least one bitof the two bits represents an encryption control; setting at least oneof the two bits subsequent to the start code into the sector unit dataso as to represent that the data has been encrypted, when the sectorunit data is encrypted; encrypting the converted data; and performing anencoding process for the encrypted data and recording the encoded dataon a recoding medium; wherein data of one sector of the sector unit datais composed of 2048 bytes, wherein the encrypting step is performed byencrypting data after bit 64, and in which the two bits subsequent tothe start code are located in a same position for a plurality of formatsystems, wherein the converting step comprises the steps of: judgingwhether the input data is to be converted into the sector unit datacorresponding to an MPEG encoding rule; and converting the input datacorresponding to the MPEG encoding rule, when the judged resultrepresents that the input data is to be converted into the sector unitdata corresponding to the MPEG encoding rule, and wherein when thejudged result represents that the input data is not to be converted intothe sector unit corresponding to the MPEG encoding rule, the convertingstep further comprises the step of: adding random number data to thesector unit data so that the random number data is followed by the startcode and the two bits.
 3. A recording apparatus, comprising: aconverting portion for converting input data into sector unit data thatstarts with a header including two bits subsequent to a start codewherein at least one bit of the two bits represents an encryptioncontrol; a setting portion for setting at least one of the two bitssubsequent to the start code into the sector unit data so as torepresent that the data has been encrypted, when the sector unit data isencrypted; an encrypting process portion for performing an encryptingprocess on setting portion output data; an encoding process portion forperforming an encoding process for output data to record the encryptingportion output data; a judging portion for judging whether the inputdata is to be converted into the sector unit data corresponding to anMPEG encoding rule; and a recording portion for recording encodingportion output data of the encoding process portion to a recordingmedium; wherein data of one sector of the sector unit data, which isinput by the converting portion, is composed of 2048 bytes, wherein whenthe data converted by the converting portion is to be encrypted, theencrypting process portion is configured to encrypt data after bit 64 ofthe converted sector unit data, in which the two bits subsequent to thestart code are located in a same position for a plurality of formatsystems, wherein when the judged result of the judging portionrepresents that the input data is to be converted into the sector unitdata corresponding to the MPEG encoding rule, the converting portion isconfigured to convert the input data corresponding to the MPEG encodingrule, and wherein when the judged result of the judging portionrepresents that the input data is not to be converted into the sectorunit corresponding to the MPEG encoding rule, the converting portion isconfigured to add random number data to the sector unit data so that therandom number data is followed by the start code and the two bits.
 4. Adata transmitting method, comprising the steps of: converting input datainto sector unit data that starts with a header including two bitssubsequent to a start code wherein at least one bit of the two bitsrepresents an encryption control; setting at least one of the two bitssubsequent to the start code into the sector unit data so as torepresent that the data has been encrypted, when the sector unit data isencrypted; encrypting the converted data; and performing an encodingprocess for the encrypted data and transmitting the encoded data;wherein data of one sector of the sector unit data is composed of 2048bytes, wherein the encrypting step is performed by encrypting data afterbit 64 of the sector unit, in which the two bits subsequent to the startcode are located in a same position for a plurality of format systems,wherein the converting step comprises the steps of: judging whether theinput data is to be converted into the sector unit data corresponding toan MPEG encoding rule; and converting the input data corresponding tothe MPEG encoding rule, when the judged result represents that the inputdata is to be converted into the sector unit data corresponding to theMPEG encoding rule, and wherein when the judged result represents thatthe input data is not to be converted into the sector unit correspondingto the MPEG encoding rule, the converting step further comprises thestep of: adding random number data to the sector unit data so that therandom number data is followed by the start code and the two bits.